This invention relates to an improved torque apparatus operable for use to tension flexible bands to secure freight or restrain cargo during transport. More particularly, this invention relates to a novel torque tool apparatus used for securing and restraining undesired movement of drums, boxes, rigid and flexible containers, palletized or not palletized, within the interior of a truck body, a railroad car, an intermodal container, and the like.
In the United States most overland shipping is accomplished using either a tractor/trailer truck combination, often referred to descriptively as an eighteen wheeler, or via railroad boxcars and/or truck trailers mounted on flatcars. Truck trailers are typically forty five, forty eight or fifty three feet in length and are often loaded with cargo in containment enclosures such as fifty five gallon closed head drums, super sacks or plastic reinforced bags, plastic wrapped bundles, cased goods, metal coils, specialty heavy paper rolls, plastic or metal containers mounted on pallets, and the like. Although each containment enclosures or bundles may be quite heavy and stationary at rest, the mass of a transport load can produce considerable momentum force as a truck or rail car is placed in motion.
Rail cars may be made up by a coupling or humping process within a switching yard. When a railroad car is rolled into a stationary string of cars, the impact causes the car couplings to lock together with a jolt. This impact can apply a significant force to cargo within the rail car. Moreover, during transport, railway cars are subject to braking forces, run-in and run-out coupler impact over grades, rail vibration, dips in the track, and swaying. In a similar manner trucks are subject to stopping and starting forces, emergency braking, bumps and swaying from uneven road beds, centrifugal forces on curves, vibration, etc. which tend to shift loads.
In addition to the above discussed overland shipping, most shipments for export, both in the United States and abroad, are placed into intermodal containers. These containers have standardized dimensions of twenty or forty feet in length and are fabricated with steel, corrugated sidewalls which are structurally self-supporting and rugged. Several intermodal containers may be stacked on top of each other for transport by sea, rail, or road. Within the containers, drums, boxes, etc. hold actual product as noted above.
The cargo of these intermodal containers experience various forces throughout the course of movement, as noted above in connection with overland transport, such as, acceleration, centrifugal loads, braking, vibration, etc. In addition, intermodal containers, when loaded onto ships for ocean passage, are subjected to wave forces including: yaw, pitch, heave, sway, and surge. Each of these forces has the potential to impart a substantial force onto the contents within an intermodal container. In this, when a container changes direction or speed, cargo within the container tends to continue along the previously existing path until it contacts an interior wall of the container. Without some type of restraint and/or cushioning system, the cargo builds up considerable momentum, independent of the container. The amount of momentum is equal to the mass of a load multiplied by its velocity. In the case of large cargo loads, even a small change in velocity or direction can generate substantial forces.
When cargo contacts the interior walls or doors of a container, the force necessary to reduce its momentum to zero must be absorbed by the goods and/or the container. Such forces can result in damage to the cargo, damage to the interior walls or doors of the container, damage to the cargo packing, and may create dangerous leaks if the cargo is a hazardous material. Accordingly, it is undesirable to permit cargo to gain any momentum independent of a container during transport. This is accomplished by restraining the cargo within the container so that the cargo and the container are essentially united and operationally function as one object during transport.
In order to secure a load during transport and minimize undesired shifting and damage the load containment enclosures are often secured to the floor and/or sides of the trailer or boxcar by specially fabricated wood framing, floor blocking, rubber mats, steel strapping, heavy air bags, etc. Each of these previously known systems for securement have limitations associated with construction cost, lack of strength sufficient to secure heavy loads, operator skill in securing cargo, etc. Moreover, although rear doors of a trailer may be relied on to at least partially secure non-hazardous materials such as food-stuffs, tissue or soft paper products, furniture, appliances, etc., for hazardous materials, and many other types of loads, the rear doors of a container may not be used to even partially secure a load. In fact, in order to comply with Department of Transportation Regulations and Bureau of Explosives, hazardous materials are not permitted to contact rear doors during an impact.
In the past, various dunnage materials have been utilized within trailers and/or intermodal containers to eliminate unwanted movement or shifting of a load during transport. The drums, boxes, or other containers have been restrained in several different ways. Primarily, cargo was stabilized by a method of load-locking and lumber bracing. This system involves strategically placing lumber between a load face and the rear doors of a container. This, however, can be a costly, time consuming, and generally inefficient means of securing a load. In this, the blocking process requires carpenters and is often outsourced to contractors. Moreover, wooden barriers can be time consuming to install. Still, further wood bracing can be somewhat brittle and subject to failure as a result of an abrupt impact.
In addition to the above, conventional methods of load-blocking with lumber bracing simply can not perform some tasks. For example, the most efficient means of filling an intermodal container is eighty, fifty-five gallon drums, double stacked in a twenty-foot long container. However, if eighty barrels are loaded there are only approximately four inches between the load face and rear doors of the container. Four inches is not enough space to put sufficient lumber to adequately brace a load of eighty drums. Consequently, when wood bracing is utilized as a system of restraint, shippers are forced to ship containers that are not filled to capacity. This reduces transport efficiency and increases transportation costs. Moreover, some types of wood, such as conifer woods, are not acceptable to cross international boundaries without certification of special fumigation or heat treatment processing. The International Plant Protection Convention (“IPPC”) has issued “Guidelines for Regulating Wood Packaging Material in International Trade” having specific sections, requirements and limitations with respect to wood dunnage that has been accepted by numerous countries including the United States.
The Department of Transportation has established a standard to determine if a particular restraint system is capable of adequately securing hazardous cargo. In certain instances, conventional load-locking and lumber bracing has not received approval to ship hazardous cargo.
Still further in some instances a trailer or boxcar may be used for shipping where only a partial load is carried. Moreover, a partial load might be positioned within a central location of the trailer. In this instance it may be impractical to construct wooden front and rear dunnage sufficient to secure a load where the front of the trailer is not utilized.
Other known means of restraint such as ropes, metal or plastic straps or stands and the like appearing in the past have tended to exhibit impaired performance and are often not functionally suitable to restrain loads under even moderate conditions. Consequently, a need exists for securing lading in truck trailers, boxcars, and intermodal containers that is functionally effective, cost-efficient, labor-efficient, and able to comply with Department of Transportation and Bureau of Explosives regulations. Still further, a need exists for securement systems that cooperate with enhanced strength characteristics of flexible load restraining strips, such as identified in the patents noted above and applications for patent below, and limit cargo travel within a container.
More specifically, at least one method and apparatus for restraining cargo movement which overcomes some of the foregoing limitations is disclosed in U.S. Pat. No. 4,264,251, of common assignment with the subject application. The invention disclosed in that patent comprises sealing strips that are adhered to mirror image opposing sidewalls of a container and a joining mechanism that binds the ends of the strips together into a secure and taut restraint.
In the '251 patent, flexible securement strips are applied in a manner similar to hanging wallpaper, where an adhesive is applied onto a surface within a trailer. Then a retaining strip is applied to the adhesive. In addition to this requirement of a separate adhesive, systems appearing in the past sometimes encountered problems associated with weakness at the joints. At the juncture where the strips came together, an opportunity existed for slippage of the joined panels. Moreover, intermodal containers have corrugated walls as noted above. These corrugations make applying a restraining strip to a separate adhesive, which may not have an even application, substantially more difficult.
In addition to the restraining system disclosed in U.S. Pat. No. 4,264,251 other systems have been developed that provide enhanced operating characteristics and advantages, as discussed in the above identified U.S. Pat. Nos. 6,089,802; 6,227,779 and 6,607,337. The disclosures of these prior four patents, of common assignment as the subject application, are hereby incorporated by reference as though set forth at length.
Further to these prior systems of securing lading in truck trailers, railroad cars, and intermodal containers increasing attention has been placed on securing heavier and denser loads, including hazardous materials, without abandoning the advantages achieved by previously known commercial systems. Moreover, there is interest in decreasing the elastic and/or plastic elongation and enhancing the vertical securement function so that hazardous materials can be transported with enhanced efficiency and security. In this regard it would be desirable to utilize an eighty, fifty five gallon, drum load within a conventional intermodal container. In this arrangement four steel drums need to be positioned next adjacent to the rear door of an intermodal container. In the past, issues have existed with respect to unacceptable travel of loads which may even come into contact with rear doors of the container during impact. As noted above, for hazardous loads, load contact with the rear doors is not acceptable by HazMat regulations.
In addition to the above, other restraining systems known in the past required multiple elements which were cumbersome to store, were arduous to install, and often required a degree of skilled labor. Systems using straps, nails, anchors, or bolts all require substantial storage space even when not in use. Furthermore, such systems increase the safety risk to the workers restraining the cargo. Still further such systems have often been unable to satisfy safety and travel limits imposed by regulatory bodies in various countries.
In addition to the above concerns, systems and procedures used in the past relying on accessories located within the cargo container often were not able to secure a partial load. That is, if the load does not extend to the front or rear of the container, such as a centrally located load, the necessary anchors may not be available in an area where they can be effectively used.
The foregoing limitations in cargo and freight restraint have been addressed by the applicant here through the invention of certain flexible strip or bands of reinforced or monolithic materials that have been disclosed in the following four of applicant's applications for patent filed on Dec. 9, 2003: Ser. No. 10/730,024 “Laminated Cargo Restraint System and Method” which issues as U.S. Pat. No. 6,923,609 on Aug. 2, 2005, Ser. No. 10/730,025 “Monolithic Cargo Restraint System and Method” which issued as U.S. Pat. No. 6,896,459, currently pending Ser. No. 10/730,042 “Cross-Weave Cargo Restraint System and Method,” and currently pending Ser. No. 10/730,040 “Cargo Restraint System and Method.” The disclosures of these applications are hereby incorporated by reference as though set forth at length. These stronger and less elastic flexible restraining strips provide enhanced tension systems that will require more uniform tension and higher tension in order to fully utilize the advances provided by these flexible restraining strips.
In each of applicant's foregoing identified applications opposing flexible strips are releasably self-adhered to an interior surface of a transport container such as a box car, truck trailer or intermodal container. The container is then loaded with cargo or freight and the opposing strips are wrapped across a load face and overlapped. At the overlap junction a rod with a central kerf is inserted over the overlapped ends and then a pair of wrenches are applied to one end of the close pin rod and the rod is twisted to tension the flexible strips around the load. A self-adhering patch is then placed across the junction to secure the twisted ends of the flexible strips together and the rod is withdrawn.
Securement implements of this type exhibit certain limitations. In this, handling the ends of two, overlapped, flexible strips which are usually fifteen inches wide along with a torque rod and two wrenches can be somewhat challenging for an installer. In addition to being cumbersome because of the number of pieces need to be managed the devices that are rugged enough to apply significant tension to the restraining strips are often heavy or bulky to manage. In addition, the torque rod often tends to skew or twist which may create an uneven tension across the securement strip. It will be appreciated that if the tension imparted to the top of a flexible strip is greater than the tension at the bottom of the strip an intended uniform restraining force across the entire fifteen inch strip is compromised.
The problems suggested in the preceding are not intended to be exhaustive but rather are among many which may tend to reduce the effectiveness of cargo restraining systems known in the past. Other noteworthy problems may also exist; however, those presented above should be sufficient to demonstrate that cargo-restraining torque systems appearing in the past will admit to worthwhile improvement.